Choosing the Right Sheet Metal for Your Ductwork

Efficient ductwork is essential to ensure any HVAC system operates properly and at optimal levels. The purpose of ductwork is to direct air from your HVAC equipment and circulate it throughout a building.

There are a variety of different types of ductwork materials in use throughout construction, including fiberboard, fiberglass, and flexible ducts, but rigid sheet metal is the most common. Sheet metal is an excellent material choice for heating and cooling equipment because it enhances the performance of duct components. Made from steel or aluminum, sheet metal ducts offer increased durability, are easy to clean, simple to install, maintain, and repair, and can withstand high temperatures, dramatic temperature fluctuations, and environmental elements.


But how do you decide which metal to use for your ductwork? Keep reading to understand the benefits of each type of sheet metal so you can make the right choice for your building.


Choosing the Right Sheet Metal

Your choice of sheet metal for ductwork will depend on your budget and goals. Let’s take a look at the pros and cons of these three main types.


Galvanized Mild Steel

One of the most trusted sheet metal options for HVAC ductwork is based on galvanized mild steel with a rust-resistant zinc coating. This design is widely used due to its customizability and ability to air loss and keep energy bills at a minimum. Galvanized mild steel HVAC ductwork’s smooth surface helps improve airflow compared to other materials and helps resist mold and fungus growth. Galvanization helps protect steel from red rust, strengthens the integrity of the steel, and resists scratches.


While safe against red rust, galvanized steel can develop white rust over time if exposed to moisture. And, galvanization can be a costly process, which may cause some to seek other materials and methods.


Stainless Steel

Stainless steel sheet metal ducts do a great job resisting corrosion and moisture, making it a top choice among industries like food processing, laboratory, pharmaceutical, chemical manufacturing, and more. Stainless steel is also an effective duct material for containing chemical fumes and hazardous exhausts in large commercial and industrialized projects. Swimming pool facilities benefit greatly from the advantages of stainless steel with a variety of applications but offer significant value with their exceptional water resistance.


Stainless steel’s extreme durability and resistance to corrosion from harsh chemicals and highly saline substances make it a valuable material for both indoor and outdoor ductwork and substantially reduces the frequency that repairs and replacements may be required. Its rigidity makes it an excellent choice for moving high volumes of air, and it can generally be manipulated and welded more easily than aluminum.


The only real downside to choosing stainless steel as a ductwork material is that compared to galvanized steel or aluminum, stainless steel can be more costly in some cases. And, while its rigidity is often seen as a benefit, it may have downsides in some projects where the malleability of aluminum is preferred.



Due to its lightweight and corrosion resistance, aluminum is another popular choice for ductwork. It’s a reliable material both indoors and out, is easy to install, and can be easily cut and bent to fit any shape. The main downsides to aluminum are that it’s not as strong as heavy-duty stainless steel or galvanized mild steel and can be prone to oxidation.


Getting Started with Custom Ductwork

When planning an HVAC or duct fabrication project, working with an experienced shop with the tools and skills to handle all your needs is essential. Any basic ductwork can be designed with CAD software, but a high-quality HVAC system takes professional expertise to account for the heating and cooling needs of each room, offer guidance on the size of the system, and come prepared with the right tools, equipment, and knowhow at every stage. The right duct fabrication specialist will also be able to help you determine the best materials for your situation.


APEX’s full-service mechanical and fabrication solutions for large-scale HVAC systems and custom ductwork for any plumbing or HVAC ductwork or mechanical system, including steam, condensate, chilled water, heating hot water, potable water, gas, drainage systems, and associated equipment. We work with various metals, including galvanized mild steel, stainless steel, aluminum, copper, and more. Our crews are qualified for any custom sheet metal, plumbing, or HVAC project, from design to build to installation, and are ready to help make your next project a success. Contact us today to speak with an expert.